langs(3P) Sun Performance Library langs(3P)NAME
langs: clangs, dlangs, slangs, zlangs - returns the value of the one-
norm, or the Frobenius-norm, or the infinity-norm, or the element with
largest absolute value of a general real matrix A in sparse format.
SYNOPSIS
#include <sunperf.h>
float slangs(char *norm, SuperMatrix *A)
double dlangs(char *norm, SuperMatrix *A)
float clangs(char *norm, SuperMatrix *A)
double zlangs(char *norm, SuperMatrix *A)
float slangs_64(char *norm, SuperMatrix_64 *A)
double dlangs_64(char *norm, SuperMatrix_64 *A)
float clangs_64(char *norm, SuperMatrix_64 *A)
double zlangs_64(char *norm, SuperMatrix_64 *A)
PURPOSElangs returns the value of the one-norm, Frobenius-norm, the infinity-
norm, or the element with largest absolute value of a general real
matrix A in sparse format.
langs returns the value
norm = 'M' or 'm': max(abs(A(i,j)))
norm = '1', 'O' or 'o': norm1(A)
norm = 'I' or 'i': normI(A)
norm = 'F', 'f', 'E' or 'e': normF(A)where norm1 denotes the one-norm of a matrix (maximum column sum), normI
denotes the infinity-norm of a matrix (maximum row sum) and normF denotes the
Frobenius-norm of a matrix (square root of sum of squares). Note that
max(abs(A(i,j))) is not a matrix norm.
ARGUMENTS
char *norm (input)
Specifies the value to be returned in langs as described above.
SuperMatrix *A (input/output)
A general matrix in sparse format with dimensions (A->nrow,
A->ncol).
COPYRIGHT
Copyright (c) 2003, The Regents of the University of California,
through Lawrence Berkeley National Laboratory (subject to receipt of
any required approvals from U.S. Dept. of Energy)
SEE ALSO
SuperMatrix
http://crd.lbl.gov/~xiaoye/SuperLU/
James W. Demmel, Stanley C. Eisenstat, John R. Gilbert, Xiaoye S. Li
and Joseph W. H. Liu, "A supernodal approach to sparse partial pivotā
ing", SIAM J. Matrix Analysis and Applications, Vol. 20, Num. 3, 1999,
pp. 720-755.
6 Mar 2009 langs(3P)